Electric heating unit or element



Feb. 14, 1928. 1,659,479

A. BROWN ELECTRIC HEATING UNIT 0R ELEMENT Filed March 23, 1923 Patented F eh. 14,1928.

fa -EA b J.

ALFRED BROVIN, 01" GORE, NEW ZEALAND.

ELECTRIC HEATZIFTG UNIT OR ELEMENT.

Application filed March 23, 1923, Serial No. 627,218, and in New Zealand September 17, 1921.

This invention relates to electrical heating devices for heating or boiling water in hettles, tea urns, barber's urns, doctors and dentists sterilizing outfits and other similar purposes and has for its objects to provide a cheaper, compact, easily accessible, and easily repaired heating device, which will not readily get out of order.

lVith the above and other objects in view, the invention consists in the construction, combination and arrangement of devices hereinafter described and claimed.

Referring now to the preferred embodiment of the invention disclosed in the accompanying drawings in which Figure 1 is a side elevation of a device constructed in accordance with this invention designed to be connected to ordinary public supply cur rent at, say, for instance, 230 volts, direct showing the elongated outer shell to which are attached two heating units or" exactly similar design and shape, Figure 2 is a sectional plan of the same showing the means for attaching the heating unit to the outer shell also the attachment of the outer shell to the radiator or water jacket of engine, Figure 3 is a part sectional side elevation of one of the heating units showing the construction and attachment of the various parts, Figure 4 is a side elevation of the insulator on which is wound the Iii-chrome wire, Figure 5 is a perspective view of the steel butt plate showing the perspective positions of the terminal post and the terminal post extension.

In accordance with this invention there is provided a high voltage device adapted for utilization direct from the main service supply of electric current. This comprises an outer cast metal shell having flanges 26 which are attachable to the radiator or water jacket 27 of engine by means of studs 28 and nuts 29. An opening 30 in the radiator or water jacket 27 is necessary to allow the circulating water therein to flow into the interior 31 of the shell 25 and around they protective chamber 59. The opposite end or head 32 of the shell 25 is horedand tapped to receive the threaded heads 33 of the two heat unit bodies. The externally rounded head 34 of the heat unit body is preferably provided with a number of shallow holes 35 to accommodate a half round spanner for tightening in position, a copper asbestos washer 36 being placed between head 34 and top 32 at the shell 255 Internally, the

34 is shaped to receive a porcelain insulator 3?, the outer face 38 of the head 34 being spun over the outer taper or cone 39 ot the insulator 3? thereby locking it securely. The insulator 3'Tis adapted to receive the two terminal posts 40 and 41, a cylindrically shaped recess 42 being provided to accommodate the head 43 of the post 40. The terminal post 41 passes through a preferably mica washer 44 and is screwed into the steel butt plate 45 which is tapped to receive it. The butt plate 45 is also tapped to receive the screwed end 46 of the terminal post eX- tension 47 so that the extension 47 is 1ongitud'inally central with the insulator 37. Mounted upon the extension 47 is a preterably fire clay or mica insulator 48 upon the outer face of which is a spiral groove 49 upon which is wound the coil of ni-chrome wire 50. Mica washers 51 and 52 are pro vided at either end ot the insulator 48. The copper washer 53 and nut 53 enable the insulator to be rigidly connected to the terminal post 41. The ni-chrome resistance wire is preferably wound in the form of a spring and is further wound upon the spiral groove 49 of the insulator 48. The end 54 of the wire 50 is passed through small holes 55 in the mica washers 51 and 44 and brazed or otherwise suitably secured to the slot 56 in the head 43 ot the terminal post 40. The other end 57 is passed through the small hole 58 in the mica washer 52 and clamped to form a contact between the nut 53 and copper washer 53. A preferably brass'tubular shell 59 of an internal diameter to accuratelv fit over the mica washers 44. 51 and 52, and the end 60 of the insulator 37 is brazed or soldered to the inner end of the screwed portion 33 of the head 34 thus forming a partial vacuum chamber. To the opposite end of the tubular shell 59 is soldered a brass or steel cap 61 to form a watertight joint. A suitable filling ot pref-' erbaly powdered quartz (32 is provided to prevent displacement of the iii-chrome wire coil 50. and for the purpose of assisting the conduction of heat from the coil 50 to the tubular shell 59 which forms the protective chamber and thence to the water surrounding same. A preferably mica cylinder 62 may be provided within the tubular shell 59 to eitectively insulate the ni-chrome coil wire 50 from tuloular shell 59.

Locking nuts 63 and terminal nuts 64 provided to secure reaps niinal posts a and il to the'insulator 37, and the wires carrying the current to the nal posts and 41. Vires65, 66 and 67 are shown in Figure l to illustrate the path of the electricrcur-r rent through the device.

In operation the double pole. system of wiring is used, viz those portions of the dev ce through which the current is designed co-pass shown in Figure 2 are insulated from the body or the unit which comprises the head ga'with its screwed or threaded eX-f tension 38, the tubular sheil59 and cap 61.

' Current enters terminal post 40 from wire 59 thus setting 65. passing through and heating Hl-ChIOlDG wire coil 50 returning via extension post dflbutt plate to terminal post 41. lVhere more. than one unit is employed as shown in Figure l the units are connected by wire .66, the current passing through the second unit in the manner already described, the current passing from terminal post 41 of the final unit to return'wire 67. If de-, sired as many as three units may be grouped in seriesas hereinbetore described. The deuce-is preferably placed low down on the radlator or water acket of engine in a hori- Vzontal position as shown in Figure 1, the water passing 1nto the outer shell 25 comes in series chamber and around said core and coil and a V conductor extending through said insulator,

said chamber forming structure and said core, saidrheating coilbeing connectedto said conductor at a point exterior of the inner end of said chamber forming structure.

2. An electric heating unit comprising a casing to contain water, said chamber being open at its inner end andprovided at its inner end with an outwardly extending flange whereby said casing may be secured on thewall of awater jacket or the like,f

insulator on tendin theretarou h' a structure formin C b 7 D aprotective chamber extending from said insulator into said casing, and a heating element in said'protective chamber and electrically connected to said posts, one or, said conducting posts also extending through said protective cl'iamb'errv V i 3. An electric heating unit comprising a casing having a threaded opening, a bushing threaded in said opening, an insulator in bushing, a structure forming a chamber attached to said bushing and extending into said casing, an insulating core in said chamher, a heating coil in said chamber, and spirally arrangedon said core, a conductor post for said heating coil extending through said insulator and also extending through said core and saidchamber: and to-which one end of said heating core is connected, a second contact element for said heating- :core comprising a conductor post whichfalso extends through said insulator,.and a filling of refractory heat conducting comminuted material in said chamber and around said core and-said heatingcoil. 7

In witness whereof I attlx'my signature.

ALFRED BROWN. 

